Apparatus and method of water culture and plant handling method

Abstract

A water culture apparatus wherein air space sections are formed between plant containers and a nutrient solution when rafts are floated in a water culture tank filled with the nutrient solution. The plant containers are inserted in vertically oriented channels provided in the raft. The air space sections are formed in order that the plant containers do not get submerged in the nutrient solution. The plants are cultivated by: gradually moving the raft from one end to another end of the water culture tank, movement of the raft corresponding to a state of growth of the plants so that the plants supported by the plant containers reach the other end by the time the plants have grown as a result of having absorbed nutrients from the nutrient solution; and harvesting the plants when each of the rafts reaches the other end of the water culture tank. The plants are handled by: sowing several seeds into each of the plant containers, the seeds in each of the plant containers corresponding in number to a shipping unit of the plants; and preparing the plant containers along with the plants contained therein for shipping once the plants have grown.

What is claimed is: 
     
       1. A water culture apparatus, comprising: a water culture tank;   a nutrient solution in said water tank;   rafts floating on said nutrient solution;   vertically oriented channels, comprising ends, in said rafts;   supporting sections extending from the ends of said channels which support plant containers; and   plant an indent space containers inserted in said vertical channels;   wherein said plant containers are disposed above said nutrient solution a distance sufficient to provide an air space between the plant containers and the nutrient solution so that the plant containers do not get submerged in the nutrient solution.   
     
     
       2. A water culture apparatus as set forth in claim 1, wherein each of the supporting sections has base surface sections which contact with base surfaces of the plant containers, the base surface sections being located above the nutrient solution so as to enable the distance from the nutrient solution to the plant containers to be adjusted. 
     
     
       3. A water culture apparatus as set forth in claim 2, wherein a width of each of the base surface sections is less than a width of each of the vertically oriented channels. 
     
     
       4. A water culture apparatus comprising: a water culture tank;.   a nutrient solution in said water tank;   rafts floating on said nutrient solution;   vertically oriented channels in said rafts; and   plant containers inserted in said vertical channels;   wherein said plant containers are disposed above said nutrient solution a distance sufficient to provide an air space between the plant containers and the nutrient solution so that the plant containers do not get submerged in the nutrient solution wherein upper protruding sections are disposed along a periphery of each of the vertically oriented channels to an extent sufficient to prevent such excess water as collects on a surface of each of the rafts in the vicinity of the vertically oriented channels from flowing into the plant containers.   
     
     
       5. A water culture apparatus comprising: a water culture tank;   a nutrient solution in said water culture tank;   rafts floating on said nutrient solution;   vertically oriented channels in said rafts;   plant containers inserted in said vertical channels; and   lower protruding sections which are disposed on an under surface of each of the rafts so that a gap is formed between rafts which are adjacent to each other.   
     
     
       6. A water culture apparatus as set forth in claim 4, further comprising lower protruding sections which are disposed on an under surface of each of the rafts so that a gap is formed between rafts which are adjacent to each other. 
     
     
       7. A water culture apparatus as set forth in claim 5, wherein the lower protruding sections are disposed so as to loosely fit into the vertically oriented channels upon rotation of alternating rafts relative to each other by 180°. 
     
     
       8. A water culture apparatus as set forth in claim 6, wherein the lower protruding sections are disposed so as to loosely fit into the vertically oriented channels upon rotation of alternating rafts relative to each other by 180°. 
     
     
       9. A water culture apparatus as set forth in claim 1, wherein the vertically oriented channels of the rafts widen as the vertically oriented channels approach an under surface of each of the rafts, in order to facilitate removal of the plant containers. 
     
     
       10. A water culture apparatus comprising: a water culture tank;   a nutrient solution in said water culture tank;   rafts floating on said nutrient solution;   vertically oriented channels in said rafts;   plant containers inserted in said vertical channels; and   lower inclined-surface sections, which incline towards an inner direction in each of the rafts, formed on side surfaces of the rafts in order to prevent nutrient solution from rising to an upper surface of each of the rafts due to capillary action at contacting parts between the rafts when a plurality of rafts are floated in the water culture tank.   
     
     
       11. A water culture apparatus comprising: a water culture tank;   a nutrient solution in said water culture tank;   rafts floating on said nutrient solution;   vertically oriented channels in said rafts; and   plant containers inserted in said vertical channels; wherein said rafts comprise two lateral side surfaces which are orthogonal to a direction of movement of said rafts on said nutrient medium, wherein a concave section is disposed in each of the rafts on one of said two lateral side surfaces, and wherein     a convex section is disposed in a position opposed to the concave section on another of the two lateral side surfaces so as to fit into the concave section,   wherein the concave section and the convex section serve to reduce resistance due to contact between the rafts and the water culture tank by fixing mutual positions of the rafts when a plurality of the rafts are floated in the water culture tank and transported therein.